7.08 The round of 32 pairings are determined by means of a draw. This round is played under the knockout system, on a home and away basis (two legs). The UEFA administration ensures that the following principles are respected.
a) Clubs from the same association cannot be drawn against each other.
b) The 12 UEFA Europa League group-winners and the 4 best third-ranked teams in the UEFA Champions League group stage are drawn against the 12 UEFA Europa League group runners-up and the remaining third-ranked teams in the UEFA Champions League group stage.
c) The winners and runners-up of the same group cannot be drawn against each other.
d) The UEFA Europa League group-winners and the four best third-ranked in the UEFA Champions League group stage play the return leg at home.